what if everyone uses it (or other genetic treatments) for augmentation or design? there is a critical mass when compulsory loses its meaning, I think. you don't have to eliminate cash by law for example if no business will take it.
I think there is an essential difference between "you have to do X because it is mandated" and "you practically have to do X in order to keep up". For one, the latter scenario is essentially more democratic than the former, it first requires some critical mass of people voluntarily (in the strongest sense of the word) deciding that they are better off with X, whereas the former may only require a decision from a relatively small number of authorities. This puts strong restrictions on what X could possibly be: for example, you would never have people sterilizing themselves because some critical mass of other people are sterilizing themselves. I will also point out that your argument applies to technological progress in general and is not specific to gene editing.
EDIT: I may have misunderstood you, I interpreted your comment to be about the hypothetical scenario where most people have genetically modified themselves into being "super heroes" and now the people who haven't can't keep up with the rest of society, so it becomes a practical necessity without being legally required. On second reading though I'm not sure if that's what you meant.
